On May 20, 2015, the DC Water authority, the District of Columbia, the
Environmental Protection Agency, and the Department of Justice announced an
agreement to modify a 2005 legal settlement affecting the Clean Rivers Project that
impacts the Potomac River and Rock Creek. The agreement allows modifications to the Clean Rivers Project that include installation of large-scale
green infrastructure and a reduction of reliance on the Potomac River Tunnel, a very large underground structure that will run beneath part
of the Georgetown waterfront and downstream to below the Kennedy Center. During periods of heavy rainfall, the tunnel will store
contaminated runoff until it can be properly processed.Under the modified plan, the tunnel’s capacity would be 30 million
gallons instead of the original 58 million gallons.Maps posted on the DC Water web page linked immediately
below show that the western terminus of the tunnel would not be
within the C&O Canal National Historical Park, as earlier envisioned, but
at a site downriver within Georgetown: http://www.dcwater.com/education/green.cfm#topThe modified plan that includes the shorter version of the Potomac River Tunnel includes long-term green infrastructure actions described in a DC Water briefing released on June 10, 2015:https://www.dcwater.com/education/gi-images/Public_Outreach_Meeting.pdf

The National Park Service and DC Water are preparing an
Environmental Impact Statement (EIS) on the tunnel.The web page linked below this paragraph provides
information about the project, including detailed displays shown at a public
meeting held on July 31, 2014. The period for public comments on the scope
of the EIS closed on September 2, 2014. (A comment by the Defenders
coalition was submitted on August 24, 2014.)On Jan. 29, 2015, consulting parties were
briefed under Section 106 of the National Historic Preservation Act; displays
from that meeting were added to the project website. A tentative
schedule called for a public meeting to introduce alternatives in the winter of
2014-15, and a public hearing on a draft Environmental Impact Statement in
spring 2015 (more recently, DC Water has indicated that this public event will likely take place in autumn 2015):http://parkplanning.nps.gov/projectHome.cfm?projectID=50548